R4 Ballot #1 (Mixed Normative/Trial use) Current Build
This is the FHIR R4 Mixed Normative/Trial Use Ballot #1, and the version for the Cologne Connectathon in May 2018. The current version is R3 . See the ballot introduction for details about the ballot. For a full list of available versions, see the Directory of published versions and Timelines for an explanation of STU and other statuses.
FHIR Infrastructure Work Group Maturity Level : 5 Ballot Status : Normative

Normative Candidate Note: This page is candidate normative content for R4 in the Infrastructure Package . Once normative, it will lose it's Maturity Level, and breaking changes will no longer be made.

Extension
Standards Status This element has a standards status of "Normative" which is different to from the status of the whole resource
Definition

Optional Extension Element - found in all resources.

Control 1..1
Type Element
Requirements

The ability to add extensions in a structured way is what keeps FHIR resources simple.

Invariants
Defined on this element
ext-1 : Rule Must have either extensions or value[x], not both ( expression : extension.exists() != value.exists(), xpath: exists(f:extension)!=exists(f:*[starts-with(local-name(.), 'value')])) value.exists()
Extension.url
Definition

Source of the definition for the extension code - a logical name or a URL.

Control 1..1
Type uri
Comments

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

Extension.value[x]
Definition

Value of extension - may be a resource or one of a constrained set of the data types (see Extensibility in the spec for list).

Control 0..1
Type *
[x] Note See Choice of Data Types for further information about how to use [x]